A hologram or optical variable device is a photographic image giving an observer a seemingly three-dimensional view of the represented object. The three-dimensional effect is produced by exposing a photographic recording medium to an interference pattern generated by a coherent beam of light (as from a laser) reflected from the subject, interacting with a beam directly from the source. The full three-dimensional effect requires illumination of the image with coherent light, but less perfect three-dimensional effects may also be observed with the hologram is illuminated with white light.
The use of holograms has become wide spread as a means for providing document verification. Important and/or sensitive documents, such as drivers licenses, credit cards and other identity and financial documents. Incorporate reflective type holograms. The security is predicted on the difficulty of reproducing holograms.
Hologram imagers have been in use for years. The prior art imagers utilize light sources, motion control means and image capturing devices to capture holographic images. The primary drawback of the prior art imaging devices is they do not capture the holographic images which are being used for the purpose of document verification. Another drawback is the required movement of the hologram, light source, lens or all of the same during image capture. Yet another drawback is the inability to image other document markings or related features associated with the document. Although the prior art devices may be suitable for the limited purpose they address, they are not suitable for capturing images of holograms and similar document markings being used for document verification.
Therefore, there continues to be the need for a holographic imaging device which captures images of holograms and similar document markings which are being used for document verification.